Coherent optical transmission uses modulation of the amplitude and phase of light, as well as transmission on two polarizations, to enable the transport of considerably more information through a fiber optic cable by transmitting multiple bits per symbol. Optical transceivers further utilize advanced signal processing techniques to perform various functions including dispersion mitigation and the like. Further, optical transceivers utilize advanced Forward Error Correction (FEC) schemes to provide additional reach and/or capacity. In operation, there are various real-time measurements that may be performed such as, for example, measurement of the Optical Signal-to-Noise Ratio (OSNR), Polarization Mode Dispersion (PMD), Polarization Dependent Loss (PDL) and the like. These various real-time measurements can be performed at an optical receiver based in part on comparing the transmitted signal with the received signal. Of course, the optical receiver does not know the actual transmitted signal, i.e., symbols and the sequence thereof. Conventionally, the optical receiver can reconstruct the transmitted signal based on hard or soft decision estimates of the received bits prior to FEC decoding. However, this reconstruction is merely an estimate of the transmitted signal and using such an estimate of the transmitted signal for the real-time measurements is imprecise and prone to errors. For example, an optical transceiver can have symbol error rates on the order of 30-40% leading to significant discrepancies between the estimated transmitted signal and the actual transmitted signal. Alternatively, training symbols may be sent periodically. Training symbols are known to the receiver a priori and as such don't convey sent information. They do, however, consume channel bandwidth resources. As a result, use of training symbols reduces the amount of information that can be sent in a given time interval.